|  | /* | 
|  | * drivers/input/touchscreen/tsc2007.c | 
|  | * | 
|  | * Copyright (c) 2008 MtekVision Co., Ltd. | 
|  | *	Kwangwoo Lee <kwlee@mtekvision.com> | 
|  | * | 
|  | * Using code from: | 
|  | *  - ads7846.c | 
|  | *	Copyright (c) 2005 David Brownell | 
|  | *	Copyright (c) 2006 Nokia Corporation | 
|  | *  - corgi_ts.c | 
|  | *	Copyright (C) 2004-2005 Richard Purdie | 
|  | *  - omap_ts.[hc], ads7846.h, ts_osk.c | 
|  | *	Copyright (C) 2002 MontaVista Software | 
|  | *	Copyright (C) 2004 Texas Instruments | 
|  | *	Copyright (C) 2005 Dirk Behme | 
|  | * | 
|  | *  This program is free software; you can redistribute it and/or modify | 
|  | *  it under the terms of the GNU General Public License version 2 as | 
|  | *  published by the Free Software Foundation. | 
|  | */ | 
|  |  | 
|  | #include <linux/module.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/input.h> | 
|  | #include <linux/interrupt.h> | 
|  | #include <linux/i2c.h> | 
|  | #include <linux/i2c/tsc2007.h> | 
|  |  | 
|  | #define TSC2007_MEASURE_TEMP0		(0x0 << 4) | 
|  | #define TSC2007_MEASURE_AUX		(0x2 << 4) | 
|  | #define TSC2007_MEASURE_TEMP1		(0x4 << 4) | 
|  | #define TSC2007_ACTIVATE_XN		(0x8 << 4) | 
|  | #define TSC2007_ACTIVATE_YN		(0x9 << 4) | 
|  | #define TSC2007_ACTIVATE_YP_XN		(0xa << 4) | 
|  | #define TSC2007_SETUP			(0xb << 4) | 
|  | #define TSC2007_MEASURE_X		(0xc << 4) | 
|  | #define TSC2007_MEASURE_Y		(0xd << 4) | 
|  | #define TSC2007_MEASURE_Z1		(0xe << 4) | 
|  | #define TSC2007_MEASURE_Z2		(0xf << 4) | 
|  |  | 
|  | #define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2) | 
|  | #define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2) | 
|  | #define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2) | 
|  | #define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2) | 
|  |  | 
|  | #define TSC2007_12BIT			(0x0 << 1) | 
|  | #define TSC2007_8BIT			(0x1 << 1) | 
|  |  | 
|  | #define	MAX_12BIT			((1 << 12) - 1) | 
|  |  | 
|  | #define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0) | 
|  |  | 
|  | #define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y) | 
|  | #define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1) | 
|  | #define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2) | 
|  | #define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X) | 
|  | #define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN) | 
|  |  | 
|  | struct ts_event { | 
|  | u16	x; | 
|  | u16	y; | 
|  | u16	z1, z2; | 
|  | }; | 
|  |  | 
|  | struct tsc2007 { | 
|  | struct input_dev	*input; | 
|  | char			phys[32]; | 
|  |  | 
|  | struct i2c_client	*client; | 
|  |  | 
|  | u16			model; | 
|  | u16			x_plate_ohms; | 
|  | u16			max_rt; | 
|  | unsigned long		poll_delay; | 
|  | unsigned long		poll_period; | 
|  |  | 
|  | int			irq; | 
|  |  | 
|  | wait_queue_head_t	wait; | 
|  | bool			stopped; | 
|  |  | 
|  | int			(*get_pendown_state)(void); | 
|  | void			(*clear_penirq)(void); | 
|  | }; | 
|  |  | 
|  | static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd) | 
|  | { | 
|  | s32 data; | 
|  | u16 val; | 
|  |  | 
|  | data = i2c_smbus_read_word_data(tsc->client, cmd); | 
|  | if (data < 0) { | 
|  | dev_err(&tsc->client->dev, "i2c io error: %d\n", data); | 
|  | return data; | 
|  | } | 
|  |  | 
|  | /* The protocol and raw data format from i2c interface: | 
|  | * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P | 
|  | * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit]. | 
|  | */ | 
|  | val = swab16(data) >> 4; | 
|  |  | 
|  | dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val); | 
|  |  | 
|  | return val; | 
|  | } | 
|  |  | 
|  | static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc) | 
|  | { | 
|  | /* y- still on; turn on only y+ (and ADC) */ | 
|  | tc->y = tsc2007_xfer(tsc, READ_Y); | 
|  |  | 
|  | /* turn y- off, x+ on, then leave in lowpower */ | 
|  | tc->x = tsc2007_xfer(tsc, READ_X); | 
|  |  | 
|  | /* turn y+ off, x- on; we'll use formula #1 */ | 
|  | tc->z1 = tsc2007_xfer(tsc, READ_Z1); | 
|  | tc->z2 = tsc2007_xfer(tsc, READ_Z2); | 
|  |  | 
|  | /* Prepare for next touch reading - power down ADC, enable PENIRQ */ | 
|  | tsc2007_xfer(tsc, PWRDOWN); | 
|  | } | 
|  |  | 
|  | static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc) | 
|  | { | 
|  | u32 rt = 0; | 
|  |  | 
|  | /* range filtering */ | 
|  | if (tc->x == MAX_12BIT) | 
|  | tc->x = 0; | 
|  |  | 
|  | if (likely(tc->x && tc->z1)) { | 
|  | /* compute touch pressure resistance using equation #1 */ | 
|  | rt = tc->z2 - tc->z1; | 
|  | rt *= tc->x; | 
|  | rt *= tsc->x_plate_ohms; | 
|  | rt /= tc->z1; | 
|  | rt = (rt + 2047) >> 12; | 
|  | } | 
|  |  | 
|  | return rt; | 
|  | } | 
|  |  | 
|  | static bool tsc2007_is_pen_down(struct tsc2007 *ts) | 
|  | { | 
|  | /* | 
|  | * NOTE: We can't rely on the pressure to determine the pen down | 
|  | * state, even though this controller has a pressure sensor. | 
|  | * The pressure value can fluctuate for quite a while after | 
|  | * lifting the pen and in some cases may not even settle at the | 
|  | * expected value. | 
|  | * | 
|  | * The only safe way to check for the pen up condition is in the | 
|  | * work function by reading the pen signal state (it's a GPIO | 
|  | * and IRQ). Unfortunately such callback is not always available, | 
|  | * in that case we assume that the pen is down and expect caller | 
|  | * to fall back on the pressure reading. | 
|  | */ | 
|  |  | 
|  | if (!ts->get_pendown_state) | 
|  | return true; | 
|  |  | 
|  | return ts->get_pendown_state(); | 
|  | } | 
|  |  | 
|  | static irqreturn_t tsc2007_soft_irq(int irq, void *handle) | 
|  | { | 
|  | struct tsc2007 *ts = handle; | 
|  | struct input_dev *input = ts->input; | 
|  | struct ts_event tc; | 
|  | u32 rt; | 
|  |  | 
|  | while (!ts->stopped && tsc2007_is_pen_down(ts)) { | 
|  |  | 
|  | /* pen is down, continue with the measurement */ | 
|  | tsc2007_read_values(ts, &tc); | 
|  |  | 
|  | rt = tsc2007_calculate_pressure(ts, &tc); | 
|  |  | 
|  | if (rt == 0 && !ts->get_pendown_state) { | 
|  | /* | 
|  | * If pressure reported is 0 and we don't have | 
|  | * callback to check pendown state, we have to | 
|  | * assume that pen was lifted up. | 
|  | */ | 
|  | break; | 
|  | } | 
|  |  | 
|  | if (rt <= ts->max_rt) { | 
|  | dev_dbg(&ts->client->dev, | 
|  | "DOWN point(%4d,%4d), pressure (%4u)\n", | 
|  | tc.x, tc.y, rt); | 
|  |  | 
|  | input_report_key(input, BTN_TOUCH, 1); | 
|  | input_report_abs(input, ABS_X, tc.x); | 
|  | input_report_abs(input, ABS_Y, tc.y); | 
|  | input_report_abs(input, ABS_PRESSURE, rt); | 
|  |  | 
|  | input_sync(input); | 
|  |  | 
|  | } else { | 
|  | /* | 
|  | * Sample found inconsistent by debouncing or pressure is | 
|  | * beyond the maximum. Don't report it to user space, | 
|  | * repeat at least once more the measurement. | 
|  | */ | 
|  | dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt); | 
|  | } | 
|  |  | 
|  | wait_event_timeout(ts->wait, ts->stopped, | 
|  | msecs_to_jiffies(ts->poll_period)); | 
|  | } | 
|  |  | 
|  | dev_dbg(&ts->client->dev, "UP\n"); | 
|  |  | 
|  | input_report_key(input, BTN_TOUCH, 0); | 
|  | input_report_abs(input, ABS_PRESSURE, 0); | 
|  | input_sync(input); | 
|  |  | 
|  | if (ts->clear_penirq) | 
|  | ts->clear_penirq(); | 
|  |  | 
|  | return IRQ_HANDLED; | 
|  | } | 
|  |  | 
|  | static irqreturn_t tsc2007_hard_irq(int irq, void *handle) | 
|  | { | 
|  | struct tsc2007 *ts = handle; | 
|  |  | 
|  | if (!ts->get_pendown_state || likely(ts->get_pendown_state())) | 
|  | return IRQ_WAKE_THREAD; | 
|  |  | 
|  | if (ts->clear_penirq) | 
|  | ts->clear_penirq(); | 
|  |  | 
|  | return IRQ_HANDLED; | 
|  | } | 
|  |  | 
|  | static void tsc2007_stop(struct tsc2007 *ts) | 
|  | { | 
|  | ts->stopped = true; | 
|  | mb(); | 
|  | wake_up(&ts->wait); | 
|  |  | 
|  | disable_irq(ts->irq); | 
|  | } | 
|  |  | 
|  | static int tsc2007_open(struct input_dev *input_dev) | 
|  | { | 
|  | struct tsc2007 *ts = input_get_drvdata(input_dev); | 
|  | int err; | 
|  |  | 
|  | ts->stopped = false; | 
|  | mb(); | 
|  |  | 
|  | enable_irq(ts->irq); | 
|  |  | 
|  | /* Prepare for touch readings - power down ADC and enable PENIRQ */ | 
|  | err = tsc2007_xfer(ts, PWRDOWN); | 
|  | if (err < 0) { | 
|  | tsc2007_stop(ts); | 
|  | return err; | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static void tsc2007_close(struct input_dev *input_dev) | 
|  | { | 
|  | struct tsc2007 *ts = input_get_drvdata(input_dev); | 
|  |  | 
|  | tsc2007_stop(ts); | 
|  | } | 
|  |  | 
|  | static int __devinit tsc2007_probe(struct i2c_client *client, | 
|  | const struct i2c_device_id *id) | 
|  | { | 
|  | struct tsc2007 *ts; | 
|  | struct tsc2007_platform_data *pdata = client->dev.platform_data; | 
|  | struct input_dev *input_dev; | 
|  | int err; | 
|  |  | 
|  | if (!pdata) { | 
|  | dev_err(&client->dev, "platform data is required!\n"); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | if (!i2c_check_functionality(client->adapter, | 
|  | I2C_FUNC_SMBUS_READ_WORD_DATA)) | 
|  | return -EIO; | 
|  |  | 
|  | ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL); | 
|  | input_dev = input_allocate_device(); | 
|  | if (!ts || !input_dev) { | 
|  | err = -ENOMEM; | 
|  | goto err_free_mem; | 
|  | } | 
|  |  | 
|  | ts->client = client; | 
|  | ts->irq = client->irq; | 
|  | ts->input = input_dev; | 
|  | init_waitqueue_head(&ts->wait); | 
|  |  | 
|  | ts->model             = pdata->model; | 
|  | ts->x_plate_ohms      = pdata->x_plate_ohms; | 
|  | ts->max_rt            = pdata->max_rt ? : MAX_12BIT; | 
|  | ts->poll_delay        = pdata->poll_delay ? : 1; | 
|  | ts->poll_period       = pdata->poll_period ? : 1; | 
|  | ts->get_pendown_state = pdata->get_pendown_state; | 
|  | ts->clear_penirq      = pdata->clear_penirq; | 
|  |  | 
|  | if (pdata->x_plate_ohms == 0) { | 
|  | dev_err(&client->dev, "x_plate_ohms is not set up in platform data"); | 
|  | err = -EINVAL; | 
|  | goto err_free_mem; | 
|  | } | 
|  |  | 
|  | snprintf(ts->phys, sizeof(ts->phys), | 
|  | "%s/input0", dev_name(&client->dev)); | 
|  |  | 
|  | input_dev->name = "TSC2007 Touchscreen"; | 
|  | input_dev->phys = ts->phys; | 
|  | input_dev->id.bustype = BUS_I2C; | 
|  |  | 
|  | input_dev->open = tsc2007_open; | 
|  | input_dev->close = tsc2007_close; | 
|  |  | 
|  | input_set_drvdata(input_dev, ts); | 
|  |  | 
|  | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); | 
|  | input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); | 
|  |  | 
|  | input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, pdata->fuzzx, 0); | 
|  | input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, pdata->fuzzy, 0); | 
|  | input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, | 
|  | pdata->fuzzz, 0); | 
|  |  | 
|  | if (pdata->init_platform_hw) | 
|  | pdata->init_platform_hw(); | 
|  |  | 
|  | err = request_threaded_irq(ts->irq, tsc2007_hard_irq, tsc2007_soft_irq, | 
|  | IRQF_ONESHOT, client->dev.driver->name, ts); | 
|  | if (err < 0) { | 
|  | dev_err(&client->dev, "irq %d busy?\n", ts->irq); | 
|  | goto err_free_mem; | 
|  | } | 
|  |  | 
|  | tsc2007_stop(ts); | 
|  |  | 
|  | err = input_register_device(input_dev); | 
|  | if (err) | 
|  | goto err_free_irq; | 
|  |  | 
|  | i2c_set_clientdata(client, ts); | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | err_free_irq: | 
|  | free_irq(ts->irq, ts); | 
|  | if (pdata->exit_platform_hw) | 
|  | pdata->exit_platform_hw(); | 
|  | err_free_mem: | 
|  | input_free_device(input_dev); | 
|  | kfree(ts); | 
|  | return err; | 
|  | } | 
|  |  | 
|  | static int __devexit tsc2007_remove(struct i2c_client *client) | 
|  | { | 
|  | struct tsc2007	*ts = i2c_get_clientdata(client); | 
|  | struct tsc2007_platform_data *pdata = client->dev.platform_data; | 
|  |  | 
|  | free_irq(ts->irq, ts); | 
|  |  | 
|  | if (pdata->exit_platform_hw) | 
|  | pdata->exit_platform_hw(); | 
|  |  | 
|  | input_unregister_device(ts->input); | 
|  | kfree(ts); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const struct i2c_device_id tsc2007_idtable[] = { | 
|  | { "tsc2007", 0 }, | 
|  | { } | 
|  | }; | 
|  |  | 
|  | MODULE_DEVICE_TABLE(i2c, tsc2007_idtable); | 
|  |  | 
|  | static struct i2c_driver tsc2007_driver = { | 
|  | .driver = { | 
|  | .owner	= THIS_MODULE, | 
|  | .name	= "tsc2007" | 
|  | }, | 
|  | .id_table	= tsc2007_idtable, | 
|  | .probe		= tsc2007_probe, | 
|  | .remove		= __devexit_p(tsc2007_remove), | 
|  | }; | 
|  |  | 
|  | static int __init tsc2007_init(void) | 
|  | { | 
|  | return i2c_add_driver(&tsc2007_driver); | 
|  | } | 
|  |  | 
|  | static void __exit tsc2007_exit(void) | 
|  | { | 
|  | i2c_del_driver(&tsc2007_driver); | 
|  | } | 
|  |  | 
|  | module_init(tsc2007_init); | 
|  | module_exit(tsc2007_exit); | 
|  |  | 
|  | MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>"); | 
|  | MODULE_DESCRIPTION("TSC2007 TouchScreen Driver"); | 
|  | MODULE_LICENSE("GPL"); |